Apparatus for making narrow sintered metal strips

ABSTRACT

BEFORE SINTERING A COMPACTED POWDER METAL WEB ISI SLIT LONGITUDINALLY INTO A PLURALITY OF RELATIVELY NARROW STRIPS BY A ROW OF THIN HIGH-SPEED SLITTING DISKS SPACED LATERALLY ON A SUPPORTING SHAFT TO PROVIDE STRIPS OF DESIRED WIDTHS WHICH MAY BE ALL OF THE SAME OR OF VARYING WIDTHS DEPENDING ON HOW THE SLITTING DISKS ARE SPACED ON THE SHAFT. SHAFTS FOR OTHER ROWS OF SLITTING DISKS WHICH MAY BE VARIOUSLY SPACED MAY BE CARRIED SQUIRREL-CAGE   FASHION IN A SUPPORTING STRUCTURE WHICH IS ROTATABLE TO BRING A SELECTED ROW OF DISKS TO CUTTING POSITION IN WHICH THE SHAFT OF THE ROW IS COUPLED TO DRIVING MEANS.

1971 M. H. MICHALAK APPARATUS FOR MAKING NARROW SINTERED METAL STRIPS Filed July 16, 1968 2 Sheets-Shoot 1 I INYENTUR. MdI'ZL/L Aha/n1 NOV. 23, 1971 M MICHALAK 3,621,527

APPARATUS FOR MAKING NARROW SINTERED METAL STRTIS Filed July 16, 1968 2 Sheets-Shun 2 United States Patent 3,621,527 APPARATUS FOR MAKING NARROW SINTERED METAL STRIPS Martin H. Michalak, 165 Kings Highway, Westport, Conn. 06880 Filed July 16, 1968, Ser. No. 745,194 Int. Cl. B221? 3/18 US. Cl. 18-9 6 Claims ABSTRACT OF THE DISCLOSURE Before sintering, a compacted powdered metal web is slit longitudinally into a plurality of relatively narrow strips by a row of thin high-speed slitting disks spaced laterally on a supporting shaft to provide strips of desired widths which may be all of the same width or of varying widths depending on how the slitting disks are spaced on the shaft. Shafts for other rows of slitting disks which may be variously spaced may be carried squirrel-cage fashion in a supporting structure which is rotatable to bring a selected row of disks to cutting position in which the shaft of the row is coupled to driving means.

This invention relates to the manufacture of sintered powdered metal strips.

Heretofore, it was proposed to provide methods and apparatus for facilitating the simultaneous production of a plurality of narrow strips of sintered metal from a wide web of compacted powdered metal as an incident to the operation of compacting the powdered metal, for instance by spacing the compacting rollers so that alternate opposite rollers on their respective shafts would overlap and form separate strips.

An object of this invention is to provide methods and apparatus for facilitating the simultaneous production of a plurality of narrow strips of sintered metal from a wide web of compacted powdered metal as it comes from the compacting unit and before it reaches the sintering furnace.

This is accomplished, according to the present invention, by providing a plurality of thin slitting disks which are spaced across the web of compacted but unsintered powdered metal and are mounted on a shaft to be power driven at high peripheral speed to sever the web into a plurality of juxtaposed parallel strips each of a desired width. The slitting disks may be equispaced or otherwise arranged on the shaft according to the widths of the strips desired.

An important feature of this invention is the provision of means whereby a plurality of rows of sets of cutting disks may be provided so that in each row the cutting disks may be spaced to cut the web into juxtaposed strips of predetermined widths while another set of cutting disks may be so spaced as to cut the web into strips of different widths, and means for bringing a selected row of slitting disks to slitting position.

For this purpose, the sets of cutting disks and the shafts on which they are respectively mounted may, according to the present invention, be mounted squirrel-cage fashion on a rotary carrier so that any particular set of slitting disks may be brought to slitting position by rotating the carrier until the desired set of cutting disks reaches slitting position. When a set of slitting disks is in slitting position, a driving connection is established between that row of disks and a driving motor.

According to the present invention, the shafts carrying the slitting disks are power driven by a drive which is positioned to engage a cooperating friction drive on the shaft for the slitting disk which is in slitting position.

Another feature of this invention is the provision of ice means for severing the web of compacted material transversely when the operation of slitting with one set of disks is to be discontinued and a new set of disks to be brought into use.

A feature of the present invention is the provision of slitting means for a web of powdered metal in which the slitting disks are so thin and rotate so fast that the web need not be backed up at the points of engagement of the slitting disks with the web by rollers or cooperating slitting wheels at the side of the web opposite the slitting disks. With this arrangement, the number of positions at which the cutting disks may be set on their respective shafts is unlimited by any requirement for backing-up the web of material to be slit.

A feature of this invention is the provision of means for rotating the carrier and automatically bringing it to position in which one set of slitting disks is adjacent the web of material in cutting position and holding the carrier in that position.

Another feature is the provision of means for interrupting the web-forming operations after a predetermined length of Web has been slit, the means for transversely severing the web being operated coordinately with the means for interrupting the formation of the web.

Other features and advantages will hereinafter appear.

In the accompanying drawings which illustrate a form of the invention at present preferred FIG. 1 is a side elevation, partly in section, of the web slitting means and showing diagrammatically means for interrupting the formation of the web and for severing the web transversely and diagrammatically the means for controlling the rotation and position of the rotary carrier.

FIG. 2 is a front view of the apparatus of the present invention with parts being shown in section.

As shown in the accompanying drawings, powdered metal is fed to a hopper 10 in any suitable manner and is compressed and drawn downwardly by rollers 11 after passing through a throat 12 of the hopper 10 to form a wide web 13 of compacted powdered metal. The web 13 falls away from the rollers 11 by gravity, being guided by a chute 14 to a slitting station 15 provided by this invention, where the web is slit into a plurality of juxtaposed narrow strips 16, FIG. 2, which then travel on rollers 17, or the like, to the sintering furnace represented at 18.

According to the present invention, the web 13 is slit into relatively narrow strips by a row of thin spaced slitting disks 19 which may be paper thin and covered or impregnated with diamond dust or other suitable abrasive material. The disks 19 of each row have hubs 20, FIGS. 1 and 2, by which they are mounted on a shaft 21 to rotate therewith. The shaft 21 has bearings 22 in side flanges 23 of a carrier frame 24 which includes a shaft 25 rotatably mounted in brackets 26 carried by a horizontal support 27. The shaft 25 at one end has a worm wheel 28 engaging a worm 29 on a shaft 30 which is driven by a motor 31 in a manner described below to move a selected row of slitting disks 19 to working position, i.e. to intersect the path of the web 13.

As shown in FIG. 1, when in working position, i.e. the position in which the slitting disks of one row are directly over the web 13 of compacted metal powder, a friction wheel 32 secured to the disk shaft 21 engages a friction wheel 33 on a shaft 34 driven by a motor 35 to drive the slitting disks 19 at high peripheral speed, the slitting disks of the other rows of disks being idle.

The motor 31 for advancing the carrier 24 is energized from a power source 36, one line 37 of which leads directly to the motor 31 while the other line 38 is connected to a starter switch 39 which is connected to a lead 40 connected to the motor 31.

Hence, so long as the switch 39 remains closed, the motor 31 will operate the drive to rotate the carrier 24.

However, to automatically rotate the carrier one step at a time, that is, to move one row of disks out of operative position and the next row into operative position, a holding circuit controlled by the carrier 24 is provided.

In the embodiment of the invention disclosed herein, the holding circuit comprises a solenoid 41, one end of which is connected by a lead 42 to the lead 40 and to a contact 44. The other end of the solenoid is connected by a lead 45 to the power line 37. An armature switch 46 for the solenoid 41 is connected by a lead 47 to a stationary contact 48, the latter being in position to be engaged by a contact 49 on a switch 50 connected by a lead 51 to the power line lead 38.

When the starter switch 39 is closed, the solenoid 41 is energized through line 38, switch 39, lines 42, 45 and the line 37. At the same time, the armature switch 46 energizing the contact 44, connects the line 47 from the switch 50 to the motor 31 through lines 42 and 40.

V The switch 50 is normally in the position shown in FIG. 1 with the contacts 48 and 49 disengaged because the V-shaped end 52 of the switch 50 rests in one of the V-notches 53 in a disk 54 fixedly secured to the carrier shaft 25 when a row of slitting disks is in operative position adjacent the web 13 of the material.

When the starter switch 39 is held closed, the motor is energized directly by the leads 40 and 37 and the carrier is rotated. This causes the switch 50 to be raised, and closes the contacts 48 and 49 so that current flo'ws from the lead 38 through the lead 51, contacts 49 and 48 to the anmature switch 46, contact 44, lead 42, and line 40 to the motor 31. A signal lamp L is included in this circuit to signify that contact has been made and the switch 39 can be released.

If the starter switch is then released, the circuit between the leads 38 and 40 will be opened and the motor circuit will be under the control of the holding circuit of the solenoid 41 and the switch 50. As soon as the carrier has rotated the desired amount, the V-shaped end 52 will enter the next V-notch 53 in the disk 54 and the flow of current from the power line will be interrupted and the solenoid 41 deenergized.

The motor may be a slow speed synchronous motor and/or be sufficiently damped or braked so as not to drift after it is deenergized but be stopped instantly.

Another feature of this invention is the provision of means for discontinuing the compacting and feeding of the web 13 of compacted powdered metal after a predetermined quantity of web has been formed and severing the web transversely after its production and feeding has stopped. This is accomplished in the form of the invention herein disclosed by providing a switch 55 in the feed line 56 of the motor 57 that drives the compacting and feeding rollers 11, and a cutoff knife 58 operated by a solenoid 59 coordinately with the deenergization of the motor 57.

Preferably the switch 55 is driven in synchronism with the compacting rollers 11 by drive means diagrammatically indicated at 60. The switch 55 is preferably a fottage indicator switch which may be adjusted by operating the knob 61 to become effective to stop the feed of the web and operate the cutoff knife after strips of determinate length have been formed, fed and slit.

Preferably, after the movement of the web has been stopped and the cutoff knife has severed the web, the operation of the driving motor 35 may be continued to slit the trailing end of the web and complete that particular work. When the next programmed work involves the making of strips of widths different from widths of the work thus completed, the starter switch is operated to rotate the disk carrier step-by-step as many times as is necessary to bring the selected row of cutting disks having the desired spacing to operating position. Of course, the starting switch 39 may be held operative until just before the desired row of cutting disks reaches the cutting position. The footage indicator switch 55 is then adjusted for the length of run of the strips to be formed and to cause the motor 57 to resume driving the compacting rollers 11.

While one row of slitting disks is in operative position, the cutting disks on another row may be adjusted to provide the widths of strips required for the next batch of work. However, it is contemplated by the present invention that extra shafts 21 containing the desired number of disks with the desired spacing may be provided and quickly interchanged with one or more of the rows of disks mounted on the carrier. For this purpose, bearings 22 for the shafts 21 have their sides 22a, FIG. 1, flattened to be received in flat-sided slots in the flanges 23. To removably hold the bearings 22 in the slots there are provided plates 22b secured to the periphery of the flanges 23 by bolts 220. Thus by removing the plates 22b, a shaft 21 with its bearings 22 may be removed from the carrier and another shaft 21 with its bearings 22 may be placed therein. 7 7

It should be understood that the peripheral speed of the cutting disks may and preferably is several times faster than the linear speed of the web so as to slit the web without applying any excessive pressure to it. Preferably the direction of rotation of the web corresponds to the direction of travel thereof.

It is well known that the thickness of the web 13 may be varied by adjustment of the compacting rollers 11 to move them closer to or further from each other.

Since, according to the present invention in the form illustrated, the slitting disks extend through and beyond the web 13, webs of substantially different thicknesses may be slit without requiring any change or adjustment of the slitting mechanism.

While the slitting disks 19 are shown as having an unbroken periphery, it should be understood that the peripheral edges of the disks may be provided with cutting teeth or be otherwise serrated.

I claim:

1. Apparatus for continuously manufacturing sintered powdered metal strips comprising means for forming and feeding a continuous wide web of compacted powdered metal at a determinate linear speed, a slitting station, means for guiding the formed web in a determinate path to said slitting station, means at said slitting station comprising a shaft extending transversely across said web, a row of slitting disks carried by the shaft to engage and slit said web longitudinally into a plurality of separate strips as the web advances through the slitting station, said slitting disks being mounted on said shaft laterally spaced from each other in accordance with the widths of the strips to be produced, means for rotating said shaft and slitting disks at a peripheral speed higher than the linear speed of the web to slit through the web and form a plurality of separate strips of desired widths, a sintering furnace in the path of the cut strips, and means for guiding the plurality of cut strips en masse into said sintering furnace to sinter the strips.

2. Apparatus according to claim 1, in which there is a plurality of said shafts, each shaft having a row of said slitting disks, a rotatable carrier, said shafts being mounted thereon squirrel-cage fashion, a driving motor for rotating said carrier to bring a selected row of said slitting disks step-by-step to position to engage and slit said web at the slitting station, a second driving motor, a driving friction wheel at the slitting station driven by said second motor and a driven friction wheel mounted on each diskcarrying shaft for engaging said driving friction wheel and driving the disk-carrying shaft which is located in slitting position.

3. Apparatus according to claim 1, in which there is a rotatable carrier, a plurality of disk-carrying shafts, said rotatable carrier supporting said shafts squirrel-cage fashion, an electric motor for rotating the carrier, driving means for connecting the motor to the carrier to rotate the same, and an electric circuit for energizing the motor to rotate said rotatable carrier to carry one shaft and its disks from slitting position and simultaneously carrying a second shaft and its disks to slitting position, and means for automatically opening said circuit to deenergize the motor when said second shaft and its disks are in slitting position.

4. Apparatus according to claim 1, in which there are means adjacent said slitting station between the web-forming means and said slitting disks for severing the wide web transversely.

5. Apparatus according to claim 1, in which the means for forming and feeding the wide web of compacted powdered metal comprises compacting rollers, an electric motor for driving the same, switch means to render said electric motor inoperative to drive the rollers and interrupt the forming and feeding of the web, and electrically operated severing means extending transversely across the path of the web between the forming means and the slitting station to sever the web transversely, said switch means having means for rendering said electrically operated severing means operative when said motor is rendered inoperative.

6. The apparatus according to claim 2, in which there is a third motor which operates said forming and feeding means for said wide web of compacted powdered metal, and means for severing said web transversely.

References Cited UNITED STATES PATENTS R. SPENCER ANNEAR, Primary Examiner U.S. Cl. X.R. 

